Drug discovery in ophthalmology: past success, present challenges, and future opportunities

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Abstract

Background

Drug discovery has undergone major transformations in the last century, progressing from the recognition and refinement of natural products with therapeutic benefit, to the systematic screening of molecular libraries on whole organisms or cell lines and more recently to a more target-based approach driven by greater knowledge of the physiological and pathological pathways involved. Despite this evolution increasing challenges within the drug discovery industry are causing escalating rates of failure of development pipelines.

Discussion

We review the challenges facing the drug discovery industry, and discuss what attempts are being made to increase the productivity of drug development, including a refocusing on the study of the basic biology of the disease, and an embracing of the concept of ‘translational research’. We consider what ophthalmic drug discovery can learn from the sector in general and discuss strategies to overcome the present limitations. This includes advances in the understanding of the pathogenesis of disease; improvements in animal models of human disease; improvements in ophthalmic drug delivery and attempts at patient stratification within clinical trials.

Summary

As we look to the future, we argue that investment in ophthalmic drug development must continue to cover the whole translational spectrum (from ‘bench to bedside and back again’) with recognition that both biological discovery and clinical understanding will drive drug discovery, providing safe and effective therapies for ocular disease.

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Pegaptanib, an anti-vascular endothelial growth factor therapy, was evaluated in the treatment of neovascular age-related macular degeneration. We conducted two concurrent, prospective, randomized, double-blind, multicenter, dose-ranging, controlled clinical trials using broad entry criteria. Intravitreous injection into one eye per patient of pegaptanib (at a dose of 0.3 mg, 1.0 mg, or 3.0 mg) or sham injections were administered every 6 weeks over a period of 48 weeks. The primary end point was the proportion of patients who had lost fewer than 15 letters of visual acuity at 54 weeks. In the combined analysis of the primary end point (for a total of 1186 patients), efficacy was demonstrated, without a dose-response relationship, for all three doses of pegaptanib (P<0.001 for the comparison of 0.3 mg with sham injection; P<0.001 for the comparison of 1.0 mg with sham injection; and P=0.03 for the comparison of 3.0 mg with sham injection). In the group given pegaptanib at 0.3 mg, 70 percent of patients lost fewer than 15 letters of visual acuity, as compared with 55 percent among the controls (P<0.001). The risk of severe loss of visual acuity (loss of 30 letters or more) was reduced from 22 percent in the sham-injection group to 10 percent in the group receiving 0.3 mg of pegaptanib (P<0.001). More patients receiving pegaptanib (0.3 mg), as compared with sham injection, maintained their visual acuity or gained acuity (33 percent vs. 23 percent; P=0.003). As early as six weeks after beginning therapy with the study drug, and at all subsequent points, the mean visual acuity among patients receiving 0.3 mg of pegaptanib was better than in those receiving sham injections (P<0.002). Among the adverse events that occurred, endophthalmitis (in 1.3 percent of patients), traumatic injury to the lens (in 0.7 percent), and retinal detachment (in 0.6 percent) were the most serious and required vigilance. These events were associated with a severe loss of visual acuity in 0.1 percent of patients. Pegaptanib appears to be an effective therapy for neovascular age-related macular degeneration. Its long-term safety is not known. Copyright 2004 Massachusetts Medical Society.

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Author and article information

Contributors

Nicholas J. D. Gower: Nicholas.gower@nhs.net

Robert J. Barry: r.j.barry@bham.ac.uk

Matthew R. Edmunds: m.r.edmunds@bham.ac.uk

Lucy C. Titcomb: lucy.titcomb@nhs.net

Alastair K. Denniston: a.denniston@bham.ac.uk

Journal

Journal ID (nlm-ta): BMC Ophthalmol

Journal ID (iso-abbrev): BMC Ophthalmol

Title: BMC Ophthalmology

Publisher: BioMed Central (London )

ISSN (Electronic): 1471-2415

Publication date (Electronic): 16 January 2016

Publication date PMC-release: 16 January 2016

Publication date Collection: 2016

Volume: 16

Electronic Location Identifier: 11

Affiliations

[ ]Queen Elizabeth Hospital Birmingham, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK

[ ]Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, UK

[ ]Birmingham and Midland Eye Centre, Sandwell & West Birmingham Hospitals NHS Trust, Birmingham, UK

Article

Publisher ID: 188

DOI: 10.1186/s12886-016-0188-2

PMC ID: 4715274

SO-VID: 9b1b8d3a-6929-41a8-b19a-223e74c0a814

License:

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License ( http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver ( http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.